Hydraulic control for hydraulic bucket having reciprocating teeth

ABSTRACT

This invention relates to a device for the hydraulic control of a bucket in public works machines provided with at least one movable tooth coupled to a hydraulic hammer, comprising at least one double-action hydraulic jack coupled between the bucket and the structural element on which said bucket is mounted to oscillate, wherein the feed conduits and the delivery conduits of the jack and hydraulic hammers coupled respectively to the bucket and to each of the movable teeth are respectively connected in parallel.

United States Patent Leyrat 1451 July 18, 1972 HYDRAULIC CONTROL FOR 1 References Cit HYDRAULIC BUCKET HAVING NI STATES PATENTS RECIPROCATING TEETH 2,606,013 8/1952 Acker ..299/67 [72] Inventor: Pierre J. Leyrat, Tfilport Fran 3,065,557 11/1962 Pewthers ..299/67 2,228,445 1/1941 De Velbiss ..299/67 [731 Asslgne i Anmyme Le Plessls-Bel- 2,423,787 7/1947 Mosena 6161.... .299/37 x levllle, France 1,464,486 8/1923 Gilman et a1. ..1 73/1s7 [22] Filed: Sept. 23, 1970 Primary Examiner-Ernest R. Purser PP 74,568 Attorney-Ward, McElhannon, Brooks & Fitzpatrick [30] Foreign Application Priority Data [57] ABSTRACT This invention relates to a device for the hydraulic control of a Sept. 29, 1969 France ..6933171 bucket in public works machines provided with at least one movable tooth coupled to a hydraulic hammer, comprising at [52] U.S. Cl least one double action hydraulic j coupled between the [5]] Int Cl i502 3/81 bucket and the structural element on which said bucket is [58] Fieid 173/46 mounted to oscillate, wherein the feed conduits and the delivery conduits of the jack and hydraulic hammers coupled respectively to the bucket and to each of the movable teet are respectively connected in parallel.

4 Claim, 3 Drawing Figures HYDRAULIC CONTROL FOR HYDRAULIC BUCKET HAVING RECIPROCATING TEETH The present invention relates to a device for the hydraulic control of a bucket in public works machines.

Certain buckets in public works machines are known whose front edge is provided with a vibrating tooth, for example actuated hydraulically.

Such a bucket has the advantage of having a good penetration, which is always an asset, more particularly for the work to be carried out in hard materials such as rocks, for example. However, it is ascertained that although the principle of such a bucket is attractive, the known embodiments do not lead to a good efficiency. The cause of this state of affairs resides in the hydraulic controls of the bucket and of the vibrating tooth, which are not combined to automatically obtain the greatest force of penetration possible.

Other buckets exist which also tend to solve the problem of the increase in the force of penetration, by the use of a vibrating edge for example, but which also lacks efficiency, similar to that which has already been mentioned moreover, for similar reasons.

However, it is advantageous to combine a special bucket with one or more vibrating teeth, as operating possibilities are obtained which are not comparable with those of the machines equipped with normal buckets.

In order to give said special buckets the efflciency which is lacking at present, the invention proposes a new hydraulic control device which automatically combines into a single control the control of movement of the bucket and that of the actuation of the vibrating tooth or teeth.

The invention therefore has for its subject a device for hydraulically controlling a bucket for public works machines provided with at least one movable tooth coupled to a hydraulic hammer and comprising at least one hydraulic double-action jack coupled between the bucket and the structural element on which said bucket is mounted to oscillate.

The feed conduits and the delivery conduits of the jack and hydraulic hammers coupled respectively to the bucket and to each of the movable teeth are respectively connected in parallel.

In addition, a non-return valve is advantageously arranged on the delivery conduit of each of the hydraulic hammers and enables the fluid to escape from the chambers of said hydraulic hammers connected to said delivery conduits.

A single non-return valve is preferably provided in the delivery circuit of the hydraulic hammers and is arranged on the common part of the delivery conduits of said hammers.

Two variant embodiments are also advantageous, one consisting in that at least one hydraulic hammer is coupled to each movable tooth, the other in that on the contrary there is only one hydraulic hammer coupled to the movable teeth.

It will further be specified that the feed of the double-action jack coupled with the bucket by the feed conduit corresponds to the penetration phase of said bucket into the material to be displaced.

The invention will be described in greater detail with reference to the accompanying drawing, in which:

FIG. 1 is an elevational view with part section of a bucket provided with a vibrating tooth actuated by a device according to the invention;

FIGS. 2 and 3 are schematic views of two variants of a control device according to the invention.

Referring now to the drawings, FIG. 1 shows a bucket 1 mounted to oscillate at the end of the balance beam 2 of a public works machine about an axis 3. A double action jack 4 is coupled between the balance beam 2 and a connection assembly 5, of the rocking lever type for example, this assembly itself being coupled to the bucket 1 for controlling its movement.

The bucket 1 itself is noteworthy in that it comprises a double base constituted by an inner base 6 and by an outer base 7 between which a cavity is made. At least one tooth 8 is mounted to slide in the cavity and opens into the front face of the bucket 1. A stop 9, unitary with the bucket 1, may cooperate with a shoulder of the tooth 8 in order to ensure its connection with said bucket 1.

Moreover, in the cavity between the bases 6 and 7 is arranged a hydraulic hammer l0 opposite the tooth 8 which is made unitary with the bucket 1 by a fixing means 11.

In fact, several teeth 8 are generally mounted on the same bucket. In a first variant embodiment, each of them is actuated by at least one hydraulic hammer, similar to hammer 10. Each hammer is referenced 10a, 10b, 100, as in FIG. 2. In a second variant, the different teeth 8 are actuated by a'single hammer.

Whether there are one or more hammers, it is advantageous to specify that there is at least one and that this hammer is connected to the pressurized hydraulic fluid feed circuit through a feed conduit such as conduits 12a, 12b, 12c relative to the hammers 10a, 10b, 10c, and through a delivery conduit 13a, 13b, 130.

Similarly, the jack 4 is connected to the pressurized fluid feed circuit by a feed conduit 14 and by a delivery conduit 15, and said conduits 14 and 15 may moreover be selectively placed in communication with a source of pressurized fluid and with a discharge tank. The feed conduit 14 is in fact so named because, when it is placed in communication with the pressurized fluid source, the bucket 1 is actuated in the direction of its penetration into the material to be displaced. In the present case of a back-acter bucket, this latter is actuated in the direction of the extension of the jack 4 or of the powerful abutment of the tooth 8 in the material.

Moreover, the delivery conduits 13a, 13b, 13c are connected to a single conduit 16, which in fact is the common part of said conduits. The delivery conduit. 15 of the jack 4 is itself connected to the conduit 16, downstream of the connections of the conduits 13a, 13b, 13c, whilst a non-return valve 17 is arranged on the conduit 16 between the connections of the conduits 13a, 13b, 13c to said conduit 16 and the connection of the conduit 15 to conduit 16.

The non-return valve 17 enables the fluid escaping from the hydraulic hammers 10a, 10b, 10c, through conduits 13a, 13b, 130, to return to the discharge tank, when the conduits 12a, 12b, 12c and conduit 14, which are connected in parallel to a single conduit 18, are placed in communication with the source of pressurized fluid by connection of said conduit 18 with said source. On the contrary, when it is the part of the conduit 16 connected to the conduit 15 which is placed in communication with the source of pressurized fluid, the nonreturn valve 17 isolates the conduits 13a, 13b, 130 from the pressurized fluid feed.

It will be noted that a variant according to the invention consists in arranging a non-return valve 17a, 17b, 17c on each of the conduits 13a, 13b, 130 (FIG. 3), by eliminating the preceding valve 17.

Moreover, the feed circuit of the hydraulic hammers is designed so that the teeth 8 are actuated by said hammers 10a, 10b, 10c, when the feed conduits 1201, 1211, are placed in communication with the source of pressurized fluid by means of the conduit 18.

The operation of a bucket provided with the control device described hereinbefore is as follows:

The conduits 16 and 18 may be placed in selective communication with the source of pressurized fluid and with the discharge tank by means of a single control, for example a slide valve.

When the bucket 1 is actuated during a penetration phase, the conduit 18 is placed in communication with the source of pressurized fluid. The pressurized fluid is therefore sent concomittantly into conduit 14, this having for its effect to bring the bucket 1 into abutment on the material to be displaced with contact of the teeth 8 on the material and to tend to dig out the material, and into conduits 12a, 12b, 12c, this having for its effect to actuate the teeth 8 and to facilitate their penetration and that of the whole bucket 1 into the material. The fluid escaping from jack 4 through conduit 15 and from the hydraulic hammers a, 10b, 10c through conduits 13a, 13b, 13c returns to the discharge tank through conduit 16. The increase in the force of penetration that is obtained by using the above described device can well be imagined, this increase being all the greater and more effective as it is at the very moment when the teeth are in contact with the material that they are actuated.

It will be noted, moreover, that if the bucket l is fed as described hereinbefore, conduit 18 in communication with the source of pressurized fluid, but is not yet in contact with the material and if the teeth 8 are therefore directed downwards, the hammers 10a, 10b, 100 are always actuated, but no longer reach the teeth 8 which have come out completely. This arrangement is advantageous, as it limits the periods of shocks of the hammers on the teeth to the periods of penetration only.

When the conduit 16 is finally connected with the source of pressurized fluid, and the conduit 18 with the discharge tank, the bucket 1 is maneuvered in reverse direction by isolating, by the non-return valve 17 or by the valves 17a, 17b, 170, the hammers 10a, 10b, 10c, from the pressurized fluid feed, thus by actuating none of said hammers, this being advantageous since the bucket l is then in discharge phase for example and not in penetration phase.

Of course, the application of this control, given in the example for a back-acter bucket, is valid for any other type of bucket, loader for example, for the shells of grab-buckets, or for the shells of grab-buckets suspended from a cable and for which the increase in the force of penetration is very advantageous, as this type of grab abuts on the material only by its own weight.

it is easily understood that, in addition to the advantage of eliminating one of the two controls (bucket and teeth) and of replacing it by a single control, the hydraulic control device according to the invention increases very substantially the performances of a given machine, the power of the machine remaining practically unchanged or having to be only very slightly increased, since the penetration is obtained by shocks of the hydraulic hammers on the teeth.

What is claimed is:

1. In an hydraulic bucket comprising a bucket pivotally mounted to a structural member, and at least one double-action hydraulic jack coupled between said bucket and said structural member to pivot said bucket, the improvement which comprises:

at least one movable tooth mounted to the front face of said bucket;

at least one hydraulic hammer mounted to reciprocate said tooth;

feed conduit means connecting in parallel said jack and hammer to provide hydraulic fluid thereto;

delivery conduit means connecting in parallel said hammer and said jack for return of said hydraulic fluid; and non-return valve means positioned on said delivery conduit means downstream of said hammer.

2. Apparatus of claim 1 wherein said bucket includes a plurality of movable teeth; a plurality of corresponding hydraulic hammers and a plurality of corresponding non-return valve means, each of said non-return valve means being positioned downstream of each respective hammer.

3. Apparatus of claim 1 wherein said feed conduit means is coupled to said jack in such manner as to correspond to the penetration phase of said bucket; and said delivery conduit means is further coupled to said jack downstream of said nonretum valve means whereby said jack may be returned upon reversal of fluid flow in said delivery conduit means.

4. Apparatus of claim 1 wherein there is a plurality of teeth and a single hydraulic hammer mounted to reciprocate said teeth. 

1. In an hydraulic bucket comprising a bucket pivotally mounted to a structUral member, and at least one double-action hydraulic jack coupled between said bucket and said structural member to pivot said bucket, the improvement which comprises: at least one movable tooth mounted to the front face of said bucket; at least one hydraulic hammer mounted to reciprocate said tooth; feed conduit means connecting in parallel said jack and hammer to provide hydraulic fluid thereto; delivery conduit means connecting in parallel said hammer and said jack for return of said hydraulic fluid; and non-return valve means positioned on said delivery conduit means downstream of said hammer.
 2. Apparatus of claim 1 wherein said bucket includes a plurality of movable teeth; a plurality of corresponding hydraulic hammers and a plurality of corresponding non-return valve means, each of said non-return valve means being positioned downstream of each respective hammer.
 3. Apparatus of claim 1 wherein said feed conduit means is coupled to said jack in such manner as to correspond to the penetration phase of said bucket; and said delivery conduit means is further coupled to said jack downstream of said non-return valve means whereby said jack may be returned upon reversal of fluid flow in said delivery conduit means.
 4. Apparatus of claim 1 wherein there is a plurality of teeth and a single hydraulic hammer mounted to reciprocate said teeth. 